The proposed research explores spoken word recognition in infants and adults. Specifically, this research will explore the effects of word familiarity and phonological familiarity on sensitivity to phonetic features during word recognition. With this integrative approach, potential parallels between the two populations can be explored, providing insight about the continuity of the functional architecture underlying word recognition throughout the lifespan. A more complete picture of the mechanisms underlying spoken word recognition is essential for a better understanding of developmental and traumatic language disorders. Two primary methodologies will be employed-the Intermodal Preferential Looking Paradigm and eye-tracking-to assess spoken word processing in infants and adults, respectively. Previous research has demonstrated that eye movements are closely time-locked to lexical processing. These on-line measures will be exploited to probe sensitivity to the phonetic structure of auditory input under conditions of high or low word and phonological familiarity.